Abstract
This cross-sectional study examines the association of time since first substance use with substance use disorders among young people in the US.
Earlier age at drug initiation has been shown to be associated with faster transition to substance use disorder (SUD).1 However, prevalence of specific SUDs as a function of time since first substance use among young people has not, to our knowledge, been investigated. We examined the prevalence of specific SUDs since first drug use (including tobacco, alcohol, cannabis, cocaine, methamphetamine, and heroin) or prescription misuse (including opioids, stimulants, and tranquilizers) in adolescents aged 12 to 17 years and young adults aged 18 to 25 years.
Methods
Data were from participants aged 12 to 25 years in the 2015 to 2018 National Surveys on Drug Use and Health (NSDUH) of the Substance Abuse and Mental Health Services Administration,1,2 excluding prescription drug data from 2005 to 2014 because not all initiation dates were collected in 2015 to 2018. Data were analyzed in July 2020. The NSDUH collects nationally representative data on substance use according to lifetime use, use in the past 12 months, and initiation date as well as SUDs (using Diagnostic and Statistical Manual of Mental Disorders [Fourth Edition] criteria) among noninstitutionalized civilian populations. This research was approved by the institutional review board at RTI International. Due to the sensitive contents of the NSDUH, the US Office of Management and Budget and the IRB at RTI International only require verbal informed consent. For respondents aged 12 to 17 years, verbal consent was received from each participant and their parent or legal guardian, or participants alone for those aged 17 years and living independently (eg, in a dormitory). Multivariable logistic regressions were conducted using SUDAAN version 11.0.1 (RTI International) to account for complex sample design and sampling weights. Two-tailed t tests were conducted, and significance was set at P < .05.
Results
Alcohol, cannabis, and tobacco were the most commonly used substances. The prevalence of lifetime substance use among adolescents in 2018 was 26.3% (95% CI, 25.4-27.2) for alcohol, 15.4% (95% CI, 14.7-16.1) for cannabis, and 13.4% (95% CI, 12.7-14.1) for tobacco; among young adults in 2018, prevalence of lifetime substance use was 79.7% (95% CI, 78.9-80.5) for alcohol, 51.5% (95% CI, 50.4-52.6) for cannabis, and 55.0% (95% CI, 53.9-56.1) for tobacco. Prevalence of SUDs differed by substance, age group, and time since initiation. Adjusted prevalence of cannabis use disorder was higher among adolescents than among young adults within 12 months of initiation (10.7%; 95% CI, 9.3-12.3 vs. 6.4%; 95% CI, 5.2-7.9) and at more than 36 months (20.1% [95% CI, 18.0-22.3] vs. 10.9% [95% CI, 10.3-11.4]) (Table). Prevalence of alcohol use disorder and nicotine dependence did not differ between the 2 groups within 12 months of initiation but was higher for young adults in subsequent periods.
Table. Prevalence of Specific Substance Use Disorders Among Individuals With Lifetime Substance Use Aged 12 to 25 Years by Time Since First Substance Usea.
| Measure | Weighted % (95% CI) | P value | ||||
|---|---|---|---|---|---|---|
| Total | Time since initiation, mo | |||||
| ≤12 | >12-≤24 | >24-≤36 | >36 | |||
| Lifetime cigarette use, age 12-17 y | ||||||
| No. | 8200 | 1900 | 2200 | 1200 | 2800 | NA |
| Past-month nicotine dependence | ||||||
| Unadjusted | 9.2 (8.4-10.0) | 5.7 (4.4-7.3) | 5.3 (4.2-6.7) | 12.8 (10.7-15.2) | 13.1 (11.6-14.7) | <.001 |
| Adjusted | NA | 6.6 (5.2-8.5) | 6.0 (4.8-7.5)b | 11.6 (9.7-13.7)b | 11.7 (10.4-13.1)b | .03 |
| Lifetime cigarette use, age 18-25 y | ||||||
| No. | 34 100 | 2000 | 2700 | 2800 | 26 500 | NA |
| Past-month nicotine dependence | ||||||
| Unadjusted | 19.5 (19.0-20.2) | 6.0 (4.9-7.4) | 9.4 (8.1-10.9) | 13.5 (12.0-15.2) | 22.4 (21.7-23.1) | <.001 |
| Adjusted | NA | 6.4 (5.2-7.8) | 9.6 (8.3-11.2) | 14.1 (12.6-15.8) | 22.2 (21.5-22.9) | <.001 |
| Lifetime alcohol use, age 12-17 y | ||||||
| No. | 18 800 | 3500 | 3300 | 2000 | 2100 | NA |
| 12-mo Alcohol use disorder | ||||||
| Unadjusted | 7.2 (6.7-7.7) | 3.9 (3.3-4.6) | 6.3 (5.5-7.1) | 9.6 (8.4-11.0) | 12.6 (11.3-14.0) | <.001 |
| Adjusted | NA | 5.6 (4.7-6.3) | 6.8 (6.0-7.6)b | 7.9 (6.9-9.0)b | 9.1 (8.2-10.2)b | <.001 |
| Lifetime alcohol use, age 18-25 y | ||||||
| No. | 54 500 | 4300 | 5900 | 6100 | 38 200 | NA |
| 12-mo Alcohol use disorder | ||||||
| Unadjusted | 12.9 (12.5-13.3) | 3.1 (2.4-3.8) | 6.1 (5.3-7.0) | 9.2 (8.3-10.2) | 15.7 (15.2-16.2) | <.001 |
| Adjusted | NA | 5.1 (4.1-6.3) | 8.4 (7.4-9.6) | 10.9 (9.9-12.0) | 14.2 (13.8-14.7) | <.001 |
| Lifetime cannabis use, age 12-17 y | ||||||
| No. | 10 800 | 3500 | 3300 | 2000 | 2100 | NA |
| 12-mo Cannabis use disorder | ||||||
| Unadjusted | 15.1 (14.3-16.0) | 8.5 (6.2-7.4) | 14.0 (12.5-15.5) | 18.7 (16.6-20.9) | 25.1 (22.8-27.6) | <.001 |
| Adjusted | NA | 10.7 (9.3-12.3)b | 14.6 (13.2-16.2)b | 16.8 (15.0-18.8)b | 20.1 (18.0-22.3)b | <.001 |
| Lifetime cannabis use, age 18-25 y | ||||||
| No. | 35 100 | 2100 | 3300 | 3800 | 26 000 | NA |
| 12-mo Cannabis use disorder | ||||||
| Unadjusted | 10.2 (9.8-10.7) | 4.8 (3.8-6.1) | 7.8 (6.7-9.0) | 9.4 (8.2-10.7) | 11.1 (10.6-11.7) | <.001 |
| Adjusted | NA | 6.4 (5.2-7.9) | 8.5 (7.4-9.8) | 9.1 (8.0-10.4) | 10.9 (10.3-11.4) | <.001 |
| Lifetime cocaine use, age 18-25 y | ||||||
| No. | 7600 | 1400 | 1200 | 3700 | 1200 | NA |
| 12-mo Cocaine use disorder | ||||||
| Unadjusted | 5.6 (5.0-6.3) | 6.2 (4.6-8.2) | 4.6 (3.5-6.1) | 4.6 (3.3-6.3) | 6.2 (5.3-7.3) | .56 |
| Adjusted | NA | 5.6 (4.2-7.4) | 4.7 (3.5-6.3) | 4.7 (3.4-6.4) | 6.4 (5.4-7.6) | .28 |
| Lifetime methamphetamine use, age 18-25 y | ||||||
| No. | 2000 | 200 | 300 | 300 | 1200 | NA |
| 12-mo Methamphetamine use disorder | ||||||
| Unadjusted | 15.9 (13.9-18.1) | 27.7 (19.4-37.9) | 14.9 (10.3-21.0) | 15.6 (11.1-21.5) | 14.5 (12.0-17.4) | .02 |
| Adjusted | NA | 24.8 (16.8-34.9) | 13.3 (9.4-18.6) | 15.4 (11.3-20.7) | 15.3 (12.7-18.3) | .03 |
| Lifetime heroin use, age 18-25 y | ||||||
| No. | 1100 | 100 | 200 | 200 | 700 | NA |
| 12-mo Heroin use disorder | ||||||
| Unadjusted | 25.9 (22.6-29.4) | 30.6 (20.8-42.6) | 26.7 (19.3-35.7) | 24.3 (17.4-32.9) | 25.3 (21.1-30.1) | .71 |
| Adjusted | NA | 30.9 (20.6-43.4) | 44.4 (32.0-57.5) | 36.9 (26.7-46.2) | 42.5 (35.4-49.9) | .30 |
Abbreviation: NA, not applicable.
Data from 2015 to 2018 National Surveys on Drug Use and Health (NSDUH). Prevalence controlled for age, sex, race/ethnicity, family income, age at first tobacco use (excluded from nicotine dependence analysis), age at first alcohol use (excluded from alcohol use disorder analysis), nicotine dependence (excluded from nicotine dependence analysis), major depressive episode, alcohol use disorder (excluded from alcohol use disorder analysis), cannabis use disorder (excluded from cannabis use disorder analysis), cocaine use or disorder (excluded from cocaine use disorder analysis), hallucinogen use or disorder, prescription tranquilizer/sedative use disorder, prescription stimulant use disorder, and prescription opioid or heroin use disorder (heroin use disorder analysis: entered prescription opioid use disorder).
Adjusted estimate for adolescents was significantly different from adjusted estimate for young adults within the same period (P < .05).
Among young adults, prevalence of lifetime cocaine, methamphetamine, and heroin use in 2018 was 11.4% (95% CI, 10.7-12.1), 2.5% (95% CI, 2.2-2.8), and 1.3% (95% CI, 1.1-1.5), respectively. Within 12 months of initiation, adjusted prevalence was higher for methamphetamine use disorder (24.8% [95% CI, 16.8-34.9]) and heroin use disorder (30.9% [95% CI, 20.6-43.4]) than for cocaine use disorder (5.6% [95% CI, 4.2-7.4]). Estimates for adolescents were not reported owing to limited samples.
Prevalence of lifetime misuse of prescription drugs in 2014 was 9.2% (95% CI, 8.7-9.7) among adolescents and 26.3% (95% CI, 25.4-27.2) among young adults. Among the population with lifetime misuse, adjusted prevalence of prescription opioid use disorder, prescription stimulant use disorder, and prescription tranquilizer use disorder were consistently higher for adolescents than for young adults (Figure). Prevalence since time of initiation for adolescents was stable for prescription opioid use disorder and decreased for prescription stimulant use disorder and prescription tranquilizer use disorder, whereas for young adults, prevalence increased for prescription opioid use disorder and was stable for prescription stimulant use disorder and prescription tranquilizer use disorder.
Figure. Adjusted Past 12-Month Prevalence of Prescription Drug Use Disorder by Time Since First Nonmedical Use.
Estimates adjusted for age, sex, race/ethnicity, family income, major depressive episode, nicotine dependence, other substance use disorder, age at first alcohol use, and age at first tobacco use.
Discussion
Using nationally representative data, we observed higher prevalence of SUD within 12 months of cannabis and prescription misuse initiation among adolescents than among young adults (eg, cannabis use disorder: 10.7% vs 6.4% within 12 months; 20.1% vs 10.9% at more than 36 months), consistent with the association of faster transition to SUDs with younger age at drug initiation. Although the American Academy of Pediatrics recommends screening for substance use among adolescents,3 the US Preventive Services Task Force recommends such screening in primary care settings only among adults.4 Our results underscore the vulnerability of adolescents to SUDs and the importance of screening for substance misuse among adolescents.
For young adults with lifetime use, prevalence within 12 months of drug initiation was high for heroin use disorder (30.9%) and methamphetamine use disorder (24.8%). Considering the high rates of opioid fatalities and rising numbers of methamphetamine deaths,5 these results highlight the urgency of prevention, screening, and treatment of SUDs in this age group.
This study has limitations. Prevalence of SUDs may have been underestimated because NSDUH excludes incarcerated individuals and homeless individuals not living in shelters and is subject to recall and social biases. Nevertheless, our results identified adolescents as highly vulnerable to SUDs, supporting the need for research to evaluate the efficacy of screening for substance use and SUDs in primary care settings and the timely treatment thereof.
References
- 1.Han B, Compton WM, Blanco C, Jones CM. Time since first cannabis use and 12-month prevalence of cannabis use disorder among youth and emerging adults in the United States. Addiction. 2019;114(4):698-707. doi: 10.1111/add.14511 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Substance Abuse and Mental Health Services Administration . National Survey on Drug Use and Health. Accessed August 14, 2020. https://www.samhsa.gov/data/data-we-collect/nsduh-national-survey-drug-use-and-health
- 3.American Academy of Pediatrics . Substance use screening and intervention implementation guide. Accessed August 3, 2020. https://www. aap.org/en-us/Documents/substanceusescreeningimplementation.pdf
- 4.Krist AH, Davidson KW, Mangione CM, et al. ; US Preventive Services Task Force . Screening for unhealthy drug use: US Preventive Services Task Force recommendation statement. JAMA. 2020;323(22):2301-2309. doi: 10.1001/jama.2020.8020 [DOI] [PubMed] [Google Scholar]
- 5.Hedegaard H, Miniño AM, Warner M; National Center for Health Statistics. Drug overdose deaths in the United States, 1999–2018. Accessed September 26, 2020. https://www.cdc.gov/nchs/products/databriefs/db356.htm